What you really need is a policy based traffic shaper which would allow you to define rules for either the hostname she is using or the hostnames/IP addresses she is connecting to.

There are lot of commercial packet shapers that you can choose from, but if you want to play around with an open source one I came across this one in a web search ("GNU Traffic Shaper") that you could give a try to:

MasterShaper is a network traffic shaper which provides a Web Interface for Quality of Servcie (QoS) functions of newer Linux 2.4- & 2.6-Kernel-Series.

I don't have direct experience with it, so take the recommendation with a cowlick sized grain of salt: It's just a pass along. You would wind up installing such a device/service in front of your router as the QOS policy manager and this would become the router for your outbound traffic.